Was it from the state you live?
If so{not knowing texas laws} a bill of sale should surfice
If not, you will have to have the other owner do a transfer from a FFL in his state to an FFL in your state which means the weapon would have to go back to the original state in order for one FFL to ship it to another FFL after fee's are paid.
If so{not knowing texas laws} a bill of sale should surfice
If not, you will have to have the other owner do a transfer from a FFL in his state to an FFL in your state which means the weapon would have to go back to the original state in order for one FFL to ship it to another FFL after fee's are paid.